An Islamic State fighter waves their flag from inside a captured government fighter jet following the battle for the Tabqa air base, in Raqqa, Syria. Photo: AP

1. Islamic State is more media sophisticated than al-Qaeda and excels in using social media as a tool of terrorism. The group's Twitter and YouTube postings in English show that the West is often their target audience.

2. Islamic State is the richest terrorist group in history. It looted at least five banks in Iraq, including Mosul's central bank branch, which yielded more than US$400 million in gold and Iraqi currency. It controls oilfields in Syria and Iraq that generate income, and it has pocketed millions of dollars in ransoms for hostages.

3. Because of Islamic State's rise to prominence, many al-Qaeda-linked groups are now pledging allegiance to it.

4. Islamic State controls territory in the heart of the Arab world, which is important for a predominantly Arab revolutionary terrorist group. The al-Qaeda core group along the Afghanistan/Pakistan border controls no territory and is dependent on Afghan and Pakistani Islamist militants who act as hosts.

5. Islamic State has evolved into a proto-state, with its own army, civil administration, judiciary and a propaganda operation.

6. Islamic State is the most heavily armed Islamist extremist group in history, having captured huge amounts of military weapons and equipment in Iraq and Syria.

7. Islamic State is out-recruiting al-Qaeda. It is estimated that 80 per cent of the foreign militants that flock to Syria join Islamic State rather than al-Qaeda's franchise.

8. Islamic State's leader, known as Abu Bakr al-Baghdadi, is charismatic, with more personal appeal for young Muslim militants than al-Qaeda's dour leader, Ayman al-Zawahiri.

9. Islamic State is better placed to get recruits into the fight. It is much easier to travel across the dissolving borders of Iraq and Syria than it is to travel to Pakistan or Afghanistan.

10. Islamic State has declared the rebirth of the caliphate and its leader has proclaimed himself to be Caliph Ibrahim.